Related Clues:

• Not fiction
• Veridicality
• Style of the Ashcan School
• Exactitude
• You'd better believe it!
• See 53-Across
• It's true
• Tell it to the judge
• Datum
• Rationality
• Certainty
• It's a fact
• 'Is that a ___?'
• Almanac tidbit
• See 35-Down